Add py34 to tox.ini
Add py34 to tox.ini

Add py34 to tox.ini.
if encounter with error 'db type could not be determined',
please remove .testrepository/ and .tox/ first, then run
'tox -e py34'

Change-Id: Ia1ef4464d0c8ac4cae5af0ef608ea1852599c1b3

openstack/python-senlinclient,stackforge/python-senlinclient,openstack/python-senlinclient,stackforge/python-senlinclient